\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\begin{tabularx}{\linewidth}{l *4{>{\centering\arraybackslash}X}} \hline\hline
                    &\multicolumn{1}{c}{(1)}&\multicolumn{1}{c}{(2)}&\multicolumn{1}{c}{(3)}&\multicolumn{1}{c}{(4)}\\
                    &  ultra-poor&   near poor&middle class& upper-class\\
\hline
In labour force     &        0.74&        0.67&        0.69&        0.71\\
                    &      (0.44)&      (0.47)&      (0.46)&      (0.46)\\
Total hours worked per year&      990.91&      767.62&      555.83&      496.83\\
                    &    (893.68)&    (811.72)&    (596.80)&    (493.42)\\
Total days worked per year&      252.06&      265.07&      303.55&      325.62\\
                    &    (136.74)&    (141.27)&    (122.21)&    (102.25)\\
Hourly income (BDT) &        5.61&        5.63&        9.83&       21.67\\
                    &     (21.22)&     (10.93)&     (38.09)&     (69.95)\\
Years of formal education&        0.56&        1.26&        1.99&        3.72\\
                    &      (1.63)&      (2.43)&      (2.99)&      (3.74)\\
Literate            &        0.07&        0.17&        0.27&        0.51\\
                    &      (0.26)&      (0.37)&      (0.44)&      (0.50)\\
Body mass index (BMI)&       18.38&       18.96&       19.49&       20.60\\
                    &      (2.40)&      (2.56)&      (2.82)&      (3.40)\\
Household Savings (1000 BDT)&        0.15&        0.40&        1.62&        8.61\\
                    &      (0.83)&      (1.24)&     (10.62)&     (29.29)\\
Productive assets (1000 BDT)&        5.03&       12.87&      145.36&      801.77\\
                    &     (30.43)&     (71.59)&    (310.50)&    (945.29)\\
Productive assets + Loans (1000 BDT)&        5.64&       14.77&      150.22&      812.83\\
                    &     (30.92)&     (72.47)&    (312.51)&    (947.65)\\
\hline
Observations        &        6732&        7340&        6742&        2215\\
\hline\hline
\end{tabularx} 
